Apparatus and method for rapidly cooling or heating the body temperature of a patient

ABSTRACT

An extracorporeal blood cooling or heating circuit includes an intravenous catheter for withdrawing a patients blood coupled to a combined pump/heat exchanger device. One or more sensors are provided upstream and/or downstream of the pump/heat exchanger device for measuring pressure, temperature, fluid flow, blood oxygenation, and other parameters. A controller is operatively coupled to the pump/heat exchanger device and the one or more sensors to control the speed of the pump inside the pump/heat exchanger device and regulate the blood temperature by controlling the operation of the heat exchanger. The combined pump/heat exchanger device includes a housing having at least one inlet and at least one outlet, a pump portion defining a blood circuit inside the housing, and a heat exchanger portion contained within the housing for selectively heating or cooling the blood.

BACKGROUND OF THE INVENTION

Field of the Invention

This invention relates, in general, to blood perfusion systems, and moreparticularly, to an apparatus and a method for rapidly cooling orheating the body temperature of a patient.

Description of the Related Art

Patients who experience severe medical trauma, such as a stroke, heartattack, or cardiac arrest, can benefit from cooling the body to belownormal body temperature shortly after experiencing the trauma. Studieshave shown that the medical outcome for such patients is significantlyimproved if they are treated within 90 minutes of arriving to thehospital. During surgery, the patient's body is typically cooled toinduce hypothermia in order to protect the organs. In certain medicalsituations, such as post-surgery, it is desirable to reheat thepatient's blood to a normal body temperature. The measure of damage tothe cardiac muscle in patients who have had an acute myocardialinfarction is directly correlative to the infarcted area. Studies haveshown that rapid increases or decreases of the patient's bodytemperature reduce the infarct size and improve recovery outcome.Similar results have been shown in stroke patients for preservingneurological function and contrast-injected patients to preserve kidneyfunction.

Existing systems and methods for reducing the temperature of a patientinclude infusion of cold saline through endovascular cooling cathetershaving separate lumens for saline flow and blood flow. Other systems andmethods rely on heating or cooling pads which are applied directly tothe patient's body. Cardiopulmonary bypass is a typical method ofcooling the patient's heart, while several similar bypass methods areknown to cool the patient's brain. These existing systems and methodsare often cumbersome and do not reduce the temperature of the patient'sbody quickly enough to have a beneficial medical outcome. Additionally,existing systems are often only capable of either heating or cooling thepatient's body, therefore requiring multiple devices present within anoperating room.

Known systems based on extracorporeal blood extraction circuitstypically have conduits carrying blood from the patient through heatexchangers in order to perform controlled heating or cooling of theblood. Conduits typically include endovascular catheters inserted intothe patient's vascular system. Heat exchangers for cooling the patient'sbody often include an ice bath for cooling the endovascular catheterdirectly or cooling the water or saline solution that is passed througha conduit in the catheter. Similarly, heat exchangers for heating thepatient's body typically include one or more heating devices for heatingthe endovascular catheter directly or heating the water or salinesolution that is passed through the catheter lumen. In certain devices,a controller may be coupled to a plurality of sensors to regulate theheat exchanger and/or the pump.

Within the prior art, U.S. Pat. No. 7,473,395 to Zviman et al. teaches ahypothermia induction device for recirculating blood through anextracorporeal circuit using a single venous access. The device includesa withdrawal pump, an infusion pump, a chiller and heat exchanger, andoptional modules for further blood treatment. A controller adjusts theoperation of withdrawal and infusion pumps based on pressures sensed incatheter lines between the patient and the device. This system is onlycapable of cooling the blood by maximizing the withdrawal rate tomaintain a predetermined temperature.

U.S. Pat. No. 7,588,549 to Eccleston is directed to a thermoelectrictemperature control device for an extracorporeal blood circuit. Thedevice includes a heat exchanger cassette having a central core and twoflow guides in thermal contact with a thermoelectric module. A pluralityof parallel channels pass through the cassette to guide blood to andfrom the device in a substantially laminar flow. A controller regulatesthe voltage and current of the thermoelectric module to control thetemperature differential produced by the device.

United States Patent Application Publication No. 2006/0293732 to Collinset al. discloses a thermoelectric cooler and heat exchanger for anintravascular heat exchange catheter. The system incorporates asecondary heat exchange element in thermal contact with a thermoelectriccooler assembly. Heat is removed from the thermoelectric cooler assemblyvia a reservoir connected to a circulating fluid supply. A controllerregulates the power level supplied to the thermoelectric coolerassembly. Optionally, the controller may also regulate the fluid flow toand from the reservoir.

Numerous disadvantages are associated with the existing devices forheating or cooling the body temperature of a patient. In most knownsystems, the heater and/or cooler is contained within a separate unitfrom the pump. This arrangement is bulky in size and therefore requiresadditional space within the operating room. Additionally, most knownsystems are capable of either heating or cooling the blood, whichrequires hospitals to get separate units for both heating and cooling.This duplication not only adds additional expense, but also furtherreduces the available space in already cramped operating rooms.Furthermore, large pump priming volume is required due to the separationof the pump from the heat exchange element. Many known systems areinefficient at adding heat to and/or removing heat from the patient'sblood and therefore require large heat exchangers having a large volumeof blood present within them.

SUMMARY OF THE INVENTION

In view of the foregoing, a need exists for an apparatus and method forrapidly cooling or heating the body temperature of a patient using anefficient pump/heat exchanger system. It is desirable to provide asystem having heat exchange capacity in order to rapidly heat or coolthe patient's blood. An additional need exists for reducing the pumppriming volume. A further need exists for a compact system that iseasily integrated within an operating room.

According to one embodiment, an apparatus for rapidly cooling or heatingthe body temperature of a patient includes a housing having at least oneinlet and at least one outlet, a pump portion contained within thehousing for extracting blood from and infusing blood to a patient'sbody, the pump portion defining a blood circuit inside the housing beingfluidly connected with at least one fluid inlet and at least one fluidoutlet, and a heat exchanger portion contained within the housing forselectively heating or cooling the blood. The heat exchanger portion maybe fluidly connected with at least one fluid inlet to receive a heatexchange fluid and at least one fluid outlet to expel the heat exchangefluid, the fluid inlet and the fluid outlet defining a fluid circuittherebetween. Alternatively, the heat exchanger portion may include aPeltier device having one or more thermoelectric modules in thermalcontact with a blood conduit.

According to another embodiment, a first inlet may be a blood inlet toreceive the blood into the housing and a first outlet may be a bloodoutlet for expelling the blood from the housing. The blood inlet and theblood outlet may be fluidly connected inside the housing via the bloodcircuit. Similarly, a second fluid inlet may be a fluid inlet to receivethe heat exchange fluid into the housing, and a second outlet may be afluid outlet for expelling the heat exchange fluid from the housing. Thefluid inlet and the fluid outlet may be fluidly connected inside thehousing via the fluid circuit such that the blood circuit and the fluidcircuit are in fluid isolation from each other inside the housing.

In accordance with another embodiment, the heat exchanger portion mayfurther include a plurality of heat exchange tubes operative for flowingthe heat exchange fluid therethrough. The plurality of heat exchangetubes may be in thermal contact with the blood circuit. The bloodcircuit may include a first chamber for receiving the blood from theblood inlet, a blood conduit for delivering the blood from the firstchamber into a pump, and a second chamber for receiving the blood fromthe pump. The second chamber may be within the heat exchanger portion ofthe housing such that blood within the second chamber is in thermalcontact with the heat exchanger portion. Desirably, the apparatus may bemade from a material having high thermal conductivity to facilitate heattransfer between the blood inside the blood circuit and the heatexchange fluid inside the fluid circuit.

According to another embodiment, an extracorporeal blood cooling orheating circuit may include a catheter for withdrawing blood from apatient into the extracorporeal blood cooling or heating circuit andinfusing blood into the patient from the extracorporeal blood cooling orheating circuit and a combined pump/heat exchanger device forselectively cooling or heating the blood. One or more sensors operativefor measuring blood temperature, pressure, flow, or oxygenation may alsobe provided. Additionally, a controller may be provided such that thecontroller is operatively connected to the combined pump/heat exchangerand one or more sensors for controlling the operation of extracorporealblood cooling or heating circuit and selectively cooling or heating theblood. The circuit may further include one or more modules operative fortreating the blood. The one or more modules may be a blood oxygenationdevice or a hemodialysis device.

According to yet another embodiment, a method for rapidly cooling orheating the body temperature of a patient may include the steps ofwithdrawing blood from a patient into an extracorporeal circuit having acombined pump/heat exchanger having a pump portion and a heat exchangerportion, selectively cooling or heating the blood within the heatexchanger portion to a desired temperature, and returning the blood tothe patient. The combined pump/heat exchanger device may include ahousing having at least one inlet and at least one outlet, a pumpportion contained within the housing for extracting blood from andinfusing blood to a patient's body, the pump portion defining a bloodcircuit inside the housing being fluidly connected with at least onefluid inlet and at least one fluid outlet, and a heat exchanger portioncontained within the housing for selectively heating or cooling theblood. The heat exchanger portion may be fluidly connected with at leastone fluid inlet to receive a heat exchange fluid and at least one fluidoutlet to expel the heat exchange fluid, the fluid inlet and the fluidoutlet defining a fluid circuit therebetween.

Further details and advantages of the various embodiments set forth inthis disclosure will become clear from the following detaileddescription read in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of one embodiment of an extracorporealblood cooling or heating circuit.

FIG. 2 is perspective view of a combined pump/heat exchanger accordingto one embodiment.

FIG. 3 is a cross-sectional view of the combined pump/heat shown in FIG.2.

FIG. 4 is a cross-sectional view of the combined pump/heat exchangeraccording to another embodiment.

FIG. 5 is a partial cross-sectional view of the pump and the heatexchanger according to a further embodiment.

DETAILED DESCRIPTION OF THE INVENTION

For purposes of the description hereinafter, spatial orientation terms,if used, shall relate to the referenced embodiment as it is oriented inthe accompanying drawing figures or otherwise described in the followingdetailed description. However, it is to be understood that theembodiments described hereinafter may assume many alternative variationsand embodiments. It is also to be understood that the specific devicesillustrated in the accompanying drawing figures and described herein aresimply exemplary and should not be considered limiting.

Referring to the drawings in which like reference characters refer tolike parts throughout the several views thereof, several embodiments ofan apparatus and method for rapidly cooling or heating the bodytemperature of a patient are presented. With reference to FIG. 1, anextracorporeal blood cooling or heating circuit 10 in accordance withone embodiment is shown. The extracorporeal blood cooling or heatingcircuit 10 includes an intravenous catheter 20 inserted into a patient30 for withdrawing the patient's blood into the extracorporeal bloodcooling or heating circuit 10. The catheter 20 is desirably inserted toa suitable point inside patient's vascular system to unload thepatient's heart during extracorporeal blood cooling or heating andreturn the blood to the patient after it has been heated or cooled.Catheter 20 may be, for example, a central venous catheter placed into apatient's neck (internal jugular vein or external jugular vein), chest(subclavian vein), or groin (femoral vein). In some embodiments,catheter 20 may be inserted, for example, into the left atrium of thepatient's heart to withdraw blood into the circuit 10. Optionally,catheter 20 may have a dual-lumen design, such that catheter 20 may beplaced into a vessel to withdraw blood and return it to a nearbylocation, desirably downstream, after the blood has been heated orcooled. In other embodiments, two independent catheters may be used,wherein one catheter is used for blood withdrawal and the other catheteris used for blood return.

With continuing reference to FIG. 1, the catheter 20 is coupled to acombined pump/heat exchanger device 40 which can selectively cool orheat the patient's blood. One or more sensors 50 may be providedupstream and/or downstream of the pump/heat exchanger device 40. The oneor more sensors 50 are operative for measuring, for example, pressure,temperature, fluid flow, blood oxygenation, and other essentialparameters. The circuit 10 may further include one or more modules 60for optional blood treatment. The one or more modules 60 may be providedupstream or downstream of the pump/heat exchanger device 40, or they maybe combined therewith. Additionally, the one or more modules 60 maycontain one or more sensors 50. The one or more modules 60 may beoperative for blood oxygenation or dialysis. For example, module 60 maybe a blood oxygenator to regulate the oxygen content in the patient'sblood.

The extracorporeal blood cooling or heating circuit 10 further includesa controller 70 operatively coupled to the pump/heat exchanger device40, one or more sensors 50, and/or one or more modules 60. Thecontroller 70 receives power from a power supply (not shown) andcontrols the operation of the circuit 10. For instance, the controller70 controls the speed of the pump inside the pump/heat exchanger device40 to regulate the blood withdrawal rate. Additionally, the controller70 monitors blood temperature provided by the one or more sensors 50 andcontrols the operation of the heat exchanger in response to thetemperature values. In some embodiments, the controller 70 may beprovided with an interface 80 to provide an indication of the operatingstatus of the circuit 10. The controller 70 may further regulate theoperation of the one or more modules 60 for further blood processing.

With reference to FIG. 2, venous blood is withdrawn by a pump 90 of acombined pump/heat exchanger device 40. As will be described herein, thepump 90 may be a conventional arterial blood pump, including, forexample, a centrifugal pump or a roller pump. The pump 90 may bemechanically driven or powered by an electric motor. In someembodiments, the pump 90 has an electromagnetic drive. The pump 90 isdirectly integrated with a heat exchanger 100 such that the pump 90 andthe heat exchanger 100 share a common housing 110. Housing 110 is shownin FIG. 2 as having a generally cylindrical shape, however other housingshapes may be used and the cylindrical shape is for exemplary purposes.

With continuing reference to FIG. 2, the combined pump/heat exchangerdevice 40 includes a plurality of fluid inlet ports and fluid outletports disposed on the housing 110. A blood inlet 120 is provided forreceiving blood from the patient 30 into the pump/heat exchanger device40. Similarly, a blood outlet 130 expels the blood once it passesthrough the pump/heat exchanger device 40. A fluid inlet 140 receivesheat exchange fluid coining into the pump/heat exchanger device 40,while a fluid outlet 150 expels the heat exchange fluid after it passesthrough the pump/heat exchanger device 40. Fittings 160 may be providedon each of the fluid inlet ports and fluid outlet ports 140, 150 forattaching conventional devices for carrying perfused blood, such as thecatheter 20. The fittings 160 may include a barbed connection, or anotherwise known connection arrangement used in the medical field, tofacilitate the coupling of tubing to the housing 110 of the pump/heatexchanger device 40.

Referring to FIG. 3, one embodiment of the combined pump/heat exchanger40 is shown. Venous blood is received inside a first chamber 170 afterpassing through the blood inlet 120. The chamber 170 is in direct fluidcommunication with the pump 90 via a blood conduit 180 extendingsubstantially along the longitudinal centerline of the housing 110. Aspreviously noted, the pump 90 desirably has the construction of aconventional blood pump. In one embodiment, the pump 90 includes a pumphousing 190 in direct fluid communication with the blood conduit 180.The pump housing 190 includes an impeller 200 driven by anelectromagnetic drive device 210. It will be apparent that several otherembodiments of the pump 90 may be utilized with the pump/heat exchangerdevice 40 in accordance with this disclosure, including a roller pump.Blood is received into the pump housing 190 (or tubing, if pump 90 is aroller pump) from the blood conduit 180 parallel to the spinning axis220 of impeller 200. Blood is circulated inside the pump housing 190 andexpelled through an outlet 230 into a second chamber 240. The secondchamber 240 is contained directly inside the heat exchanger 100 suchthat heat exchange between blood and the heat exchanger 100 takes placedirectly inside second chamber 240. After passing through the heatexchanger 100, cooled or heated blood is returned to the patient's bodythrough the blood outlet 130.

With continuing reference to FIG. 3, the heat exchange fluid, such aswater or saline solution, enters the heat exchanger 100 through thefluid inlet 140 into the first cavity 250. The first cavity 250surrounds the first chamber 170 in the upper part of the housing 110. Abottom part of the first cavity 250 includes a first perforated plate260 having a plurality of fluid openings 270 in direct fluidcommunication with a plurality of heat exchange tubes 280. Theperforated plate 260 separates the first cavity 250 of the heatexchanger 100 from the second chamber 240. The heat exchange tubes 280extend through the longitudinal length of housing 110 between the firstperforated plate 260 located at a top portion of housing 110 and asecond perforated plate 290 located at a bottom portion of housing 110.The heat exchange tubes 280 connect to a second cavity 300 providedbelow the second perforated plate 290 and provide direct fluidcommunication between the first cavity 250 and second cavity 300. Heatexchange fluid flows from the first cavity 250 to second cavity 300through the plurality of heat exchange tubes 280. Fluid outlet 150 is influid communication with second cavity 280 to expel the heat exchangefluid once it passes through heat exchanger 100.

Components of the combined pump/heat exchanger device 40 are desirablymanufactured from a material having thermal characteristics whichfacilitate heat transfer. For example, the housing 110 and internalcomponents of the pump/heat exchanger device 40 may be manufactured froma metallic or polymeric material having high thermal conductivity. Insome embodiments, the pump/heat exchanger device 40 is made from aglass, acrylic, or aluminum materials. Heat can be added or removed fromblood flowing through the pump/heat exchanger device 40 depending on thetemperature of heat transfer fluid as well as the flow rate through thepump 90. For example, blood can be cooled by circulating a heat exchangefluid through heat exchanger 100 that is cooler than the blood enteringthe pump/heat exchanger device 40. The temperature of the blood can belowered further by reducing the flow rate of pump 90 such that bloodspends more time inside the heat exchanger 100 when heat exchange fluidhas a lower temperature than the blood. Alternatively, blood can beheated by circulating a heat exchange fluid through the heat exchanger100 that is warmer than the blood entering the pump/heat exchanger. Thetemperature of the blood can be raised further by reducing the flow rateof the pump 90 such that blood spends more time inside the heatexchanger 100 when heat exchange fluid has a higher temperature than theblood.

With reference to FIG. 4, a second embodiment of the pump/heat exchangerdevice 40 is shown. In this embodiment, the heat exchange tubes 280 areoriented in a horizontal direction which is perpendicular to thelongitudinal axis of the pump/heat exchanger device 40. Venous bloodenters the pump/heat exchanger device 40 through the blood inlet 120.Blood is then received inside a blood chamber 310 in direct fluidcommunication with a blood inlet 320 on the pump 90. After passingthrough the blood chamber 310, blood is received inside the pump housing190 parallel to the spinning axis 220 of the impeller 200. Blood iscirculated inside the pump housing 190 and expelled through the bloodoutlet 130.

With continuing reference to FIG. 4, a heat exchanger cavity 330 islocated concentric to chamber 310. A plurality of heat exchange tubes280 extend through the chamber 310 between opposing ends of the heatexchanger cavity 330. Heat exchange fluid is received inside the heatexchanger cavity 330. Heat exchange fluid passes through the pluralityof heat exchange tubes 280 and also flows inside the heat exchangercavity 330 around the chamber 310. The fluid is expelled from the heatexchanger 100 through the fluid outlet 140. The heat exchangers 100shown in FIGS. 3-4 have the form of a tube-in-tube heat exchanger, wherefluid to be cooled or heated flows through a separate conduit from thecooling or heating fluid.

In an another embodiment shown in FIG. 5, the heat exchanger 100 mayutilize a thermoelectric device 350 to add or remove heat from thepatient's blood. A thermoelectric device 350 may be a Peltier cell 360having one or more thermoelectric modules 370 in direct thermal contactwith a blood conduit 380. The Peltier cell 360 operates on a Peltiereffect principle, whereby a temperature differential is created indifferent portions of the Peltier cell 360 by applying voltage tosemiconductor materials of the thermoelectric modules 370 containedbetween ceramic substrates 390. Thermal insulation (not shown) may beprovided around the heat exchanger 100 to minimize thermal loss andmaximize heat transfer efficiency.

As shown in FIG. 5, blood is passed through the pump 90 and is receivedinside a blood conduit 380 through the blood inlet 120. The bloodconduit 380 desirably has a channel 400 defining a tortuous path toincrease the amount of time blood spends inside the blood conduit 380.Blood is expelled through the blood outlet 130 located opposite theblood inlet 120. Preferably, the blood conduit 380 is made from amaterial having high thermal conductivity, such as aluminum, in order toensure efficient transfer of heat from the blood conduit 380 and Peltiercell 360. The Peltier cell 360 may further include a heat sink 410 fordissipating heat from thermoelectric device 350. A fan 420 is providedto increase the efficiency of heat removal from the heat sink 410. Morethan one Peltier cell 360 may be provided. The controller 70 desirablycontrols the operation of the thermoelectric device 350 and the fan 420.

With the basic structure of the extracorporeal blood cooling and heatingcircuit 10 according to several embodiments now described, a method forrapidly cooling or heating the body temperature will now be generallydescribed. Such a method for rapidly cooling or heating the bodytemperature of a patient may begin by inserting an intravenous catheter20 into a patient 30 to withdraw blood into the extracorporeal bloodcooling or heating circuit 10. Next step, the controller 70 may beactivated to regulate the operation of the pump/heat exchanger device40, one or more sensors 50, and one or more modules 60 to control thetemperature, pressure, and flow rate of blood flowing through thecircuit 10. Prior to activating the controller 70, the user may beprompted to initialize and configure the system via an interface 80.Venous blood from the patient 30 is withdrawn into the combinedpump/heat exchanger device 40 to be cooled or heated to a desiredtemperature. Blood is cooled or heated inside the heat exchanger 100depending on whether the heat exchange fluid that flows through the heatexchanger 100 is cooler or warmer than the blood entering the pump/heatexchanger device 40. Optionally, the blood may be passed through one ormore modules 60 to further process the blood. For example, one or moremodules 60 may be a blood oxygenating module, a hemodialysis module,etc. After passing through the circuit 10, the blood is returned to thepatient 30 in a cooler or warmer state compared to the blood withdrawnfrom the patient's body.

While embodiments of an apparatus and method for rapidly cooling orheating the body temperature of a patient are shown in the accompanyingfigures and described in the foregoing in detail, other embodiments willbe clear to, and readily made by those skilled in the art, withoutdeparting from the scope and spirit of the invention. For example, whilethe present disclosure generally discusses a centrifugal-type pump 90and tube-in-tube heat exchanger 100, it is contemplated that variousother embodiments of pump 90 and heat exchanger 100 may be equallyapplicable to the present apparatus and method. The scope of theinvention will be measured by the appended claims and their equivalents.

The invention claimed is:
 1. An apparatus for rapidly cooling or heatingthe body temperature of a patient, the apparatus comprising: a housinghaving at least one blood inlet and at least one blood outlet; a pumpportion contained within the housing for extracting blood from apatient's body through the blood inlet and infusing blood to thepatient's body through the blood outlet, the pump portion defining ablood circuit inside the housing between the blood inlet and the bloodoutlet; and a heat exchanger portion contained within the housing forselectively heating or cooling the blood, wherein the blood circuitcomprises a first chamber with a conically curved bottom wall forreceiving the blood from the blood inlet, the bottom wall of the firstchamber being in thermal contact with the heat exchanger portion; ablood conduit for delivering the blood from the first chamber into apump, the blood conduit extending through the heat exchanger portion andin thermal contact with the heat exchanger portion; and a second chamberfor receiving the blood from the pump, the second chamber being withinthe heat exchanger portion and in thermal contact with the heatexchanger portion.
 2. The apparatus according to claim 1, wherein theheat exchanger portion is fluidly connected with at least one fluidinlet to receive a heat exchange fluid and at least one fluid outlet toexpel the heat exchange fluid, the fluid inlet and the fluid outletdefining a fluid circuit therebetween.
 3. The apparatus according toclaim 1, wherein the heat exchanger portion includes a Peltier devicehaving one or more thermoelectric modules in thermal contact with ablood conduit.
 4. The apparatus according to claim 2, wherein the bloodcircuit and the fluid circuit are in fluid isolation from each otherinside the housing.
 5. The apparatus according to claim 2, wherein theheat exchanger portion further comprises a plurality of heat exchangetubes operative for flowing the heat exchange fluid therethrough, theplurality of heat exchange tubes being in thermal contact with the bloodcircuit.
 6. The apparatus according to claim 2, wherein the apparatus ismade from a material having high thermal conductivity to facilitate heattransfer between the blood inside the blood circuit and the heatexchange fluid inside the fluid circuit.
 7. An extracorporeal bloodcooling or heating circuit comprising: a catheter for withdrawing bloodfrom a patient into the extracorporeal blood cooling or heating circuitand infusing blood into the patient from the extracorporeal bloodcooling or heating circuit; a combined pump/heat exchanger device forselectively cooling or heating the blood; one or more sensors operativefor measuring blood temperature, pressure, flow, or oxygenation; and acontroller operatively connected to the combined pump/heat exchanger andone or more sensors for controlling the operation of extracorporealblood cooling or heating circuit and selectively cooling or heating theblood, wherein the combined pump/heat exchanger device comprises: ahousing having at least one blood inlet and at least one blood outlet; apump portion contained within the housing for extracting blood from thepatient through the blood inlet and infusing blood to the patientthrough the blood outlet, the pump portion defining a blood circuitinside the housing between the blood inlet and the blood outlet; and aheat exchanger portion contained within the housing for selectivelyheating or cooling the blood, wherein the blood circuit comprises: afirst chamber with a conically curved bottom wall for receiving theblood from the blood inlet, the bottom wall of the first chamber beingin thermal contact with the heat exchanger portion; a blood conduit fordelivering the blood from the first chamber into a pump, the bloodconduit extending through the heat exchanger portion and in thermalcontact with the heat exchanger portion; and a second chamber forreceiving the blood from the pump, the second chamber being within theheat exchanger portion and in thermal contact with the heat exchangerportion.
 8. The extracorporeal blood cooling or heating circuitaccording to claim 7, further comprising one or more modules operativefor treating the blood.
 9. The extracorporeal blood cooling or heatingcircuit according to claim 8, wherein the one or more modules is a bloodoxygenation device or a hemodialysis device.
 10. The extracorporealblood cooling or heating circuit according to claim 7, wherein the heatexchanger portion is fluidly connected with at least one fluid inlet toreceive a heat exchange fluid and at least one fluid outlet to expel theheat exchange fluid, the fluid inlet and the fluid outlet defining afluid circuit therebetween.
 11. The extracorporeal blood cooling orheating circuit according to claim 7, wherein the heat exchanger portionincludes a Peltier device having one or more thermoelectric modules inthermal contact with a blood conduit.
 12. The extracorporeal bloodcooling or heating circuit according to claim 7, wherein the bloodcircuit and the fluid circuit are in fluid isolation from each otherinside the housing.
 13. The extracorporeal blood cooling or heatingcircuit according to claim 7, wherein the heat exchanger portion furthercomprises a plurality of heat exchange tubes operative for flowing theheat exchange fluid therethrough, the plurality of heat exchange tubesbeing in thermal contact with the blood circuit.
 14. The extracorporealblood cooling or heating circuit according to claim 7, wherein theapparatus is made from a material having high thermal conductivity tofacilitate heat transfer between the blood inside the blood circuit andthe heat exchange fluid inside the fluid circuit.
 15. A method forrapidly cooling or heating the body temperature of a patient, the methodcomprising the steps of: withdrawing blood from a patient into anextracorporeal circuit having a combined pump/heat exchanger having apump portion and a heat exchanger portion; selectively cooling orheating the blood within the heat exchanger portion to a desiredtemperature; and returning the blood to the patient, wherein thecombined pump/heat exchanger comprises: a housing having at least oneblood inlet and at least one blood outlet; the pump portion containedwithin the housing for extracting blood from the patient through theblood inlet and infusing blood to the patient through the blood outlet,the pump portion defining a blood circuit inside the housing between theblood inlet and the blood outlet; and the heat exchanger portioncontained within the housing for selectively heating or cooling theblood, wherein the blood circuit comprises: a first chamber with aconically curved bottom wall for receiving the blood from the bloodinlet, the bottom wall of the first chamber being in thermal contactwith the heat exchanger portion; a blood conduit for delivering theblood from the first chamber into a pump, the blood conduit extendingthrough the heat exchanger portion and in thermal contact with the heatexchanger portion; and a second chamber for receiving the blood from thepump, the second chamber being within the heat exchanger portion and inthermal contact with the heat exchanger portion.
 16. The method of claim15, wherein the heat exchanger portion is fluidly connected with atleast one fluid inlet to receive a heat exchange fluid and at least onefluid outlet to expel the heat exchange fluid, the fluid inlet and thefluid outlet defining a fluid circuit therebetween.